Evaluation of the Pulp Chamber Temperature during Tooth Veneer Preparation Using Burs with Different Degrees of Wear-A Preliminary In Vitro Study

The heat produced during tooth preparation could be a source of damage for dental pulp, and many variables are involved in this process. The aim of this in vitro study was to evaluate whether the different degrees of wear of the diamond burs significantly influenced the temperature changes in the pulp chamber during tangential veneer preparation. The sample comprised 30 intact permanent monoradicular teeth, randomly assigned to three study groups of 10 teeth each, of which 5 had the pulp tissue preserved and 5 had thermoconductive paste in the pulp chamber. For prosthetic preparation, we used new burs in the first group, burs at their fifth use in the second group, and burs at their eighth use for the third group. The pulp chamber temperature was evaluated at the start, after one minute, and after three minutes of preparation, using a k-type thermocouple. The results of the three-way ANOVA and Tukey post hoc comparisons showed a highly significant effect of the time of measurement, while the pulp condition and the degree of wear of the burs had no effect. In conclusion, the different degrees of wear of conventional diamond burs do not produce statistically significant different changes in the pulp chamber temperature.

The Influence of Hydrofluoric Acid Temperature and Application Technique on Ceramic Surface Texture and Shear Bond Strength of an Adhesive Cement

All-ceramic restorations are the foundation of modern esthetic dentistry. Clinical approaches for preparation, durability, aesthetics, and repair have been reformed by the idea of adhesive dentistry. The aim of the study and the objective question was to evaluate the impact of heated hydrofluoric acid pretreatment and the application technique's influence on the surface morphology and roughness of leucite-reinforced glass-ceramic materials (IPS Empress CAD, Ivoclar Vivadent), which is fundamental for understanding the adhesive cementation process. Scanning electron microscopy was used to observe the effectiveness of the two HF (Yellow Porcelain Etch, Cerkamed) application techniques and the HF's temperature impact on the surface topography of the ceramic. Based on surface conditioning methods, the adhesive cement (Panavia V5, Kuraray Noritake Dental Inc., Tokyo, Japan) was applied to the conditioned ceramic samples and light-cured. Shear bond strength values were correlated with the micro-retentive surface texture of the ceramic. With universal testing equipment at a 0.5 mm/min crosshead speed, SBS values between the resin cement and the ceramic material were assessed until failure. Analyzing the fractured surfaces of the specimens by digital microscopy, the failure modes were divided into three categories: adhesive, cohesive, and mixed failure. Analysis of variance (ANOVA) was used to statistically analyze the collected data. The results show that alternative treatment methods affected the material's surface characteristics and have an influence on the shear bond strength.

Impact of unilateral removable partial dentures versus removable partial dentures with major connector on oral health-related quality of life of elder patients: a clinical study

OBJECTIVE

This study aimed to establish the survival rate of unilateral removable partial dentures (u-RPD) comparative with bilateral RPD (bi-RPD) with major connector in elder patients, as well as to determine both their treatment satisfaction and oral health.

METHODS

The study sample included 17 patients treated with u-RPD and 17 patients treated with bi-RPD with a major connector. The patients were followed over five years with recalls every 6 months. A 5- points Likert scale was used to determine the satisfaction of the patients. The Oral Health Impact Profile-14 (OHIP-14) questionnaire was used to evaluate their oral health after each type of administrated treatment. The local oral examined aspects included the maintenance of the abutment teeth periodontal health, the fractures of the removable dentures, the fractures of the connectors, the chipping of the aesthetic material. Kaplan-Meier survival analysis was conducted to evaluate the performance of the two treatments.

RESULTS

The mean survival time in years was 4.882 ± 0.114, 95% CI (4.659; 5.106) and 4.882 ± 0.078, 95% CI (4.729; 5.036), for the u-RPD and the bi-RPD, respectively. The five-year survival rates for the two dentures were 94.1% for u-RPD vs. 88.2% for bi-RPD with a major connector, without a statistically significant difference between them (Log-rank test χ2(1) = 0.301, p = 0.584). The patients receiving u-RPD presented significantly higher satisfaction scores compared to the patients receiving bi-RPD, 4.88 ± 0.48 vs. 4.41 ± 0.62, Mann-Whitney U test, p = 0.026.

CONCLUSION

Patients receiving u-RPD presented higher levels of treatment satisfaction and better oral health than patients receiving bi-RPD. The survival rates of the treatments u-RPD and bi-RPD were similar.

Assessment of Different Techniques for Adhesive Cementation of All-Ceramic Systems

Background and Objectives: Modern esthetic dentistry is based on all-ceramic restorations. Dentists still have reservations about using these restorations due to a lack of understanding of the cementation technique, which depends on the type of ceramic used. The aim of the study is to evaluate the approaches and practices of clinicians regarding the adhesive cementation of all-ceramic restorations. Materials and Methods: An online questionnaire regarding the use of all-ceramic restorations and their bonding methods was designed by distinguishing the cementation of oxide and silica-based ceramics. The survey included dentists practicing in Timiș County, Romania. The questionnaire and the evaluation of the answers were designed based on the techniques and evidence from the literature. Results: Considering the work experience, we obtained two groups: group 1—1 to 6 years and group 2—6 to 9+ years. The results revealed significant values when comparing the two groups in the surface protocol and decontamination (p = 0.005), type of cement used (p = 0.002), and isolation techniques (p = 0.002). Conclusions: The results show that many clinicians need additional training to improve their cementing technique and avoid the confusion caused by insufficient information about the interrelationship between the type of ceramic and the cementation procedure.

Can Dental Office Lighting Intensity Conditions Influence the Accuracy of Intraoral Scanning?

The aim of this study was to evaluate the influence of different settings of ambient light intensity inside the dental office on the accuracy (trueness and precision) of an intraoral scanner (IOS). A full crown preparation was conducted on a resin molar which was scanned using a high resolution extraoral scanner to obtain a reference model. Six light settings were chosen based on the most clinically relevant light conditions inside the workspace, and the preparation was scanned using an intraoral scanner (PlanScan, Planmeca). The obtained data was analyzed using a professional 3D quality control software (Geomagic Control X). There was no statistically relevant difference between the groups when regarding trueness, although a slight influence of the light intensity could be observed on the trueness values. Regarding precision, the best results were obtained in the 3800 lux group, with the other groups presenting close values, excepting the extreme values (400 lux and 11 000 lux) groups that proved to be the most deficient.

Zirconia Minimally Invasive Partial Retainer Fixed Dental Prostheses: Up To Ten Year Follow-Up

PURPOSE

To assess the survival rate of 3 mol % yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) minimally invasive anterior and posterior single and double partial retainer fixed dental prostheses (PRFDPs).

MATERIALS AND METHODS

Twenty-three patients (18 women and 5 men, age range: 20 to 66 years) with single-tooth gaps received 28 3Y-TZP PRFDPs. Eight PRFDPs had two partial retainers and one pontic, two PRFDPs had two partial retainers and one pontic with a mesial cantilever, and 18 PRFDPs had one retainer and one cantilever. The abutment teeth were prepared following specific guidelines for all-ceramic restorations, considering existing direct restorations, carious processes, and occlusal conditions. The restorations were made of 3Y-TZP using CAD/CAM technology. Cementation was performed either conventionally, using resin-modified glass-ionomer (n = 6), or adhesively, using dual-polymerized resin cement (n = 22). Kaplan-Meier survival analysis was conducted. A P value of .05 was considered statistically significant.

RESULTS

During the observation period (5.92 ± 1.74 years, minimum = 2 years, maximum = 10 years), three debondings occurred, all in the two-retainer group and the mandible. The survival rates for the two types of intervention were different, with 100% for a single retainer and 70% for a double retainer, but without a significant difference (log-rank test χ²(1) = 0.200, P = .655).

CONCLUSION

The 3Y-TZP PRFDPs presented in this study showed no failure when bonded and not conventionally cemented. Therefore, they can be used in cases where implant therapy is not possible or indicated.

Efficacy of PerioTabs, a NitrAdine-based gingiva brushing solution, on periodontally affected patients treated with fixed partial dentures: a randomized controlled study

Objectives: Recent data show that teeth prepared with horizontal finishing lines supporting crowns and fixed partial dentures present more periodontal disorders than untreated control teeth. Several studies have shown that NitrAdine (bonyf) induces a significant reduction of dental biofilm. The aim of this study was to demonstrate that 10-day use of PerioTabs (bonyf), a NitrAdine-based gingiva brushing solution, is effective in treating gingival inflammation of prosthodontic patients. Method and materials: Forty-nine subjects were instructed to brush their teeth, gingivae, and prostheses with the PerioTabs solution for 10 days (treatment group) and 49 with any toothpaste (control group). The initial and 11-day Plaque Index and Bleeding Index were recorded. A five-point Likert scale was used to evaluate the level of patient satisfaction. The Shapiro-Wilk statistical test was used to compare the results for the two groups. Results: Highly significant differences between the treatment and control group (P < .001) for the Plaque Index and Bleeding Index resulted. The treatment group patients' satisfaction was high: 31 (63.3%) reported the highest level, 5, on the Likert scale, and 18 (36.7%) declared they were satisfied (level 4). Conclusions: The use of a NitrAdine-based gingiva brushing solution (PerioTabs) was effective in reducing the gingival inflammation in periodontally affected patients treated with fixed partial dentures. Clinical relevance: The NitrAdine-based gingiva brushing solution (PerioTabs) was highly accepted by the patients and seems to be a promising alternative to the solutions widely used.

Selective Laser Sintering versus Selective Laser Melting and Computer Aided Design - Computer Aided Manufacturing in Double Crowns Retention

Purpose This in vitro study aimed at ascertaining the retention forces for telescopic crowns fabricated with Selective Laser Manufacturing (SLM) and Selective Laser Sintering (SLS) additive technologies, and Computer Aided Design - Computer Aided Manufacturing (CAD-CAM) subtractive technology, by using suitable materials for each.Materials and Methods Full-factorial design was employed for experimental testing, considering the following three factors: (a) inner crown material ‒ technology (zirconia ‒ CAD-CAM; metal-alloy ‒ SLS; metal-alloy ‒ SLM); (b) tooth type (canine or molar); (c) wet vs. dry conditions (i.e. either with or without artificial saliva). The roughness of the inner crowns was analyzed through atomic force microscopy. Three-way analysis of variance (ANOVA) was applied for statistical analysis, followed by Tukey's post-hoc comparisons between the crown types.Results The retention force mean values were between 3.8 N (dry, SLM) and 14.8 N (artificial saliva, SLS), with statistically significant (p<0.001) differences between the three types of inner crowns and interaction with the tooth type. No significant interaction was found between crown or tooth types and the wet vs. dry testing conditions. The zirconia crowns' retention force was significantly (p<0.001) higher compared to similar SLM crowns, with 95% CI (3.62; 5.55) N for the differences. Zirconia was significantly (p<0.001) less retentive compared to similar SLS crowns, with 95% CI (-5.99; -4.06) N for the differences. The roughness decrease and subsequent loss of retention force was the largest in zirconia.Conclusions The SLS inner crowns showed the best retention, followed by zirconia and SLM inner crows.

The impact of different Milling Machines on Marginal Fit Discrepancies of Lithium Disilicate Crowns

The goal of this study was to determine the level of various discrepancies in all-ceramic IPS e. max � lithium disilicated crowns milled with three different milling machines. A 3D printed Geller model with a preparation for all ceramic crown was scanned, then the digital design was created and 24 lithium disilicate crowns were milled using three different milling machines: Plan mill 40S (Planmeca, Helsinki, Finland), Cerec MC XL (Sirona GmbH, Germany), and one laboratory milling machine Imes-Icore 650i (Coritec, Eiterfeld, Germany). Among the three groups, the highest marginal fit accuracy was displayed by crowns fabricated by laboratory milling machine Imes-Icore 650i, followed by chairside Plan mill 40S and Cerec MC XL. The results of our study shows that llithium disilicate crowns fabricated by a laboratory milling and 2 chair-side milling machines present marginal accuracy in the acceptable clinical range.

Trueness and Precision of Two Intraoral Scanners: A Comparative In Vitro Study

The aim of this study was to evaluate the accuracy of two intraoral scanners used in the dental office. A molar fixed in a typodont was prepared for a ceramic onlay. The preparation was scanned using a high-resolution scanner (reference scanner) and saved as stereolithography (STL) format. The prepared resin molar was scanned again using the intraoral scanners, and all the scans were saved as well in STL format. All STL files were compared using metrology software (Geomagic Control X). Overlapping the meshes allowed the assessment of the scans in terms of trueness and precision. Based on the results of this study, the differences of trueness and precision between the intraoral scanners were minimal.

Clinical Factors Influence the Trueness of Intra-oral Scanning

AIMS

The aim of this in vitro study was to evaluate the influence of adjacent teeth in the trueness of digital impressions.

MATERIALS AND METHODS

In this study the first premolar on a typodont mounted in a phantom head was prepared for an all ceramic crown. Three different operators scanned the tooth with an intraoral scanner, with three different clinical scenarios: with no adjacent teeth, with one adjacent tooth and with two adjacent teeth. Resulting scans from each operator were compared with a reference scan using metrology software.

RESULTS

The results of this in vitro study showed differences of scanning trueness between each clinical simulated situation.

CONCLUSIONS

The presence of adjacent teeth can decrease the view of interproximal surfaces and may generate a less precise scan in these regions. The results of this study showed that the trueness of an intraoral digital impression is conditioned by a good visibility of the abutment.

Periodontal disease in a young Romanian convenience sample: radiographic assessment

Background

The goal of this study was to determine the distribution of periodontal disease in a population seeking oral rehabilitation in a Romanian prosthodontics department and to identify the factors associated with each type of periodontal condition.

Methods

The study population consisted of patients presenting consecutively to the Prosthodontics Department of the Faculty of Dental Medicine, Victor Babeş University of Medicine and Pharmacy, Timisoara. The diagnosis and classification of periodontal conditions, as well as dental pathologies and conditions, were based on examination of panoramic radiographs. A standardized questionnaire was administered to obtain socio-demographic characteristics (age, gender, ethnicity, education, residency, marital status), medical history, dental/periodontal history (family history of periodontal disease), and behavior (smoking, brushing, flossing and regular cleaning).

Results

Among subjects presenting to the Prosthodontics department, only 34.2% were periodontal disease-free and 65.8% had periodontal disease, of which 11.4% had aggressive periodontitis. In univariate models, age, education, marital status, smoking, and tooth number were associated with chronic periodontitis. Age, education, family history, smoking, and tooth number were associated with aggressive periodontitis. However, in a multivariable model, only age, tooth number and family history were significant.

Conclusions

This study found a high prevalence of periodontal disease in patients seeking oral rehabilitation from the Prosthodontics department. Age, tooth number and family history of periodontal disease were associated with the type of periodontal disease. These results suggest the need for periodontal examination prior to prosthetic oral rehabilitation in this population.

Powder and Powder-Free Intra-Oral Scanners: Digital Impression Accuracy

Aim

The purpose of this study was to evaluate the accuracy of digital impressions taken with two different intra-oral scanners (with and without optical powder), by dentists with different level of experience.

Material and Methods

Two intra-oral scanning devices (Apollo DI and Cerec Omnicam, Sirona Dental GmbH, Germany) were used to obtain a digital cast from scanning different preparations on a maxillary typodont. Three operator groups scanned five crown preparations using both powder and powder-free scanning systems. One group consisted of fourth year dental students, a second group consisted of prosthodontic residents, and third group consisted of prosthodontic specialists. The precision of spray application and impression expertise was compared between the three groups.

Results

The most frequently encountered errors were non-linear powder application, inappropriate intra-oral scanner manipulation, and insufficient digital data for crown fabrication.

Conclusion

Experience is needed in order to achieve high quality digital impressions. A prosthodontic specialist avoided incorrect manipulation of an intra-oral camera, uneven application of powder spray and achieved a better marginal fit.

Direct Fiber-Reinforced Interim Fixed Partial Dentures: Six-Year Survival Study

PURPOSE

Mechanical and optical studies of glass fiber composites have revealed great resistance and satisfactory bonds between the glass fibers and composite resins. This study aimed to evaluate the long-term survival of anterior and posterior direct glass fiber-reinforced composite (FRC) fixed partial dentures (FPD).

MATERIALS AND METHODS

Twenty-three patients (9 men, 14 women) aged 18 to 67 received 23 d-FRC-FPDs. The frameworks of the FPDs were unidirectional pre-impregnated glass fibers (ever Stick C&B). The retainers were inlay composite resin retainers (n1 = 19) and composite resin wings (n2 = 4). The FPD that used inlay retainers and composite resin wing retainers was called the hybrid design. The mean follow-up period was 4.91 years with 12-month check-ups performed by two independent operators. The survival rates of the glass fiber FPDs were determined.

RESULTS

Six-year survival rates for the two types of FPDs were 94.7% for the inlay retainer type versus 25% for the hybrid type, with a statistically significant difference (log-rank test χ² (1) = 11.422, p = 0.001). The inlay retainers were functional, with only one patient with a fracture line in the connector held by the glass fibers. Kaplan-Meier survival curves were drawn to show the difference between the two types of retainers.

CONCLUSION

According to the results of this study, these long-term interim FRC-FPD were resistant enough to allow mastication, minimally invasive and also esthetic, with inlay composite retainers as the better solution.

Alternative prosthodontic-based treatment of a patient with hypocalcified type Amelogenesis Imperfecta

The Amelogenesis Imperfecta is associated with malocclusion and usually requires an interdisciplinary treatment. Due to the patient's refusal of orthodontic treatment, prosthodontics‐based treatments alternative was considered and planned. The patient was treated with zirconia‐based fixed partial dentures, which resulted in improved occlusion, better oral health, and improved esthetic appearance.

Is there a relationship between oral health and diabetic neuropathy?

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus with high morbidity and mortality, and low quality of life. It has a broad spectrum of clinical forms, although distal symmetrical polyneuropathy is the most prevalent. Several oral complications including burning mouth syndrome, dry mouth, and impairment of the senses taste and smell are less-known manifestations of diabetic neuropathy and often overlooked. Periodontitis, tooth loss, and temporomandibular joint dysfunction may be also present in these patients and are equally debilitating. Periodontitis was declared the sixth complication of diabetes in 1993 and may contribute to poor glucose control. Hence, periodontitis and diabetes mutually and adversely affect each other. This review summarizes the available body of scientific literature that discusses oral manifestations in patients with diabetic neuropathy and identifies important areas where more research is needed.